1. Field of Invention
This invention relates to electrical test circuits and test instruments and specifically to circuits and instruments for detecting intermittent and continuous electrical-resistance, voltage, current, continuity, and physical parameters for detecting illumination, and temperature.
2. Prior Art
There are many electrical test instruments and circuits that are used to detect voltage, current, resistance, power interruptions, and other physical parameters such as light, and temperature.
These circuits and instruments typically utilize galvanometers, digital meters, light and, sound indicators, and cathode ray tubes. A typical multi-function meter detects electrical signals that are constant or changing slowly. An oscilloscope detects electrical signals that change rapidly and are repetitious or occurs with a period of not usually longer than several minutes. An intermittent electrical fault having a brief time duration or a physical parameter that changes rapidly but not periodically is difficult or impossible to detect with with the typical test instruments or circuits.
Most users of electrical test instrument or circuits would find desirable a device that detects intermittent electrical parameters or physical parameters that can be converted to electrical signals.